在WEBSERVICE学习中遇到的问题

向我的WEBSERVICE发了一个这样的GET类的请求
http://127.0.0.1/VegService.asmx/Getvegetable?vegetablename=cucumber
然后得到报错
 

“/”应用程序中的服务器错误。

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请求格式无法识别。

说明: 执行当前 Web 请求期间，出现未处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。

异常详细信息: System.InvalidOperationException: 请求格式无法识别。

源错误:

执行当前 Web 请求期间生成了未处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。

堆栈跟踪:

[InvalidOperationException: 请求格式无法识别。]
   System.Web.Services.Protocols.WebServiceHandlerFactory.CoreGetHandler(Type type, HttpContext context, HttpRequest request, HttpResponse response) +388
   System.Web.Services.Protocols.WebServiceHandlerFactory.GetHandler(HttpContext context, String verb, String url, String filePath) +94
   System.Web.HttpApplication.MapHttpHandler(HttpContext context, String requestType, String path, String pathTranslated, Boolean useAppConfig) +699
   System.Web.MapHandlerExecutionStep.System.Web.HttpApplication+IExecutionStep.Execute() +95
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +173

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版本信息: Microsoft .NET Framework 版本:1.1.4322.573; ASP.NET 版本:1.1.4322.573

原webservice程序如下

<%@ WebService Language="vb" Class="Vegetables.Vegservice"%>

imports system
imports system.web.services
imports system.web.services.protocols
imports system.xml

namespace Vegetables


    <webservice(namespace:="http://hx66.com/net")>public class Vegservice
        inherits system.web.services.webservice

    public enum Appearance
        Round
        Bendy
        Odd
    end enum

    Public structure Vegetable
        public VegName as string
        public VegColor as string
        public VegLooks as Appearance
        public NumberInStock as integer
    end structure
        <webmethod()>Public function GetVegetable(byval vegetablename as string) as Vegetable
            'Context.request.saveas("c:\VegServiceRequest.htm",false)
            dim result as Vegetable

            select Case vegetablename.tolower()
                case "cucumber"
                    result.VegName="Cucumber"
                    result.VegColor="Green"
                    result.VegLooks= Appearance.Bendy
                    result.NumberInStock=10
                case "sweetcorn"
                    result.VegName="Sweetcorn"
                    result.VegColor="Yellow"
                    result.VegLooks= Appearance.Odd
                    result.NumberInStock=2
                case "potato"
                    result.VegName="Potato"
                    result.VegColor="Brown"
                    result.VegLooks= Appearance.Round
                    result.NumberInStock=55
                case else
                    dim code as xmlqualifiedname
                    code=new xmlqualifiedname("Sender","http://schemas.xmlsoap.org/soap/envelope")
                    dim doc as xmldocument
                    doc=new xmldocument()
                    dim detail as xmlelement
                    detail=doc.createelement("detail")
                    dim veg as xmlelement
                    veg=doc.createelement("vegFault","vegetableName","http://www.hx66.com/net/vegservice/faults")
                    veg.innertext=vegetablename
                    detail.Appendchild(veg)
                    doc.appendchild(detail)
                    throw new soapexception("Unknown vegetable.",code,"http://www.hx66.com/net/vegservice",doc)
            end select
            return result
        end function

        <webmethod()>public function GetVegetables(byval vegetablenames as string()) as Vegetable()
            'context.request.Saveas("c:\VegServiceRequest.htm",false)
            dim results() as Vegetable
            results= new Vegetable(vegetablenames.length){}

            dim resultNum as integer
            for resultNum = 0 to results.length - 1 step resultNum + 1
                results(resultNum)=GetVegetable(vegetablenames(resultNum))
            next

            return results
        end function
    end class
end namespace    

我在机器上是装了.net framework SDK的
这种情况我也不知道是什么原因了
好像是不接受GET方法
直接在页面点击方法提交参数还是可以的。

请高手帮帮忙！！！！